Since a process of condensing polyimide and one for condensing a polyethersulfone resin from individual monomers cannot proceed together because of they require different reaction conditions, it is impossible to obtain a copolymer from direct condensation of a diamine compound and an acid dianhydride compound, which are monomers of polyimide, and a dihalogen compound and a diol compound, which are monomers of polyethersulfone. As the existing method of preparing a poly(ethersulfonimide) resin, a method of forming an imide group by cyclodehydration of tetracarboxylic dianhydride with a diamine compound having an ether sulfone moiety is known.
Basically, preparation of a poly(ethersulfonimide) resin by condensation polymerization follows a process of preparing polyimide. Since the ether sulfone moiety is included in the diamine functional group, control of copolymerization ratio is impossible and the polymer length is limited by the diamine compound used as monomer.
Meanwhile, since a process of condensing polyimide and one for condensing a polyethersulfone resin from individual monomers cannot proceed together because of they require different reaction conditions, it is impossible to obtain a copolymer from direct condensation of a diamine compound and a dicarboxylic acid compound or a diacyl halide compound, which are monomers of polyamide, and a dihalogen compound and a diol compound, which are monomers of polyethersulfone. As the existing method of preparing a poly(ethersulfonamide) resin, a method of condensing a diamine compound with a dicarboxylic acid compound or a diacyl chloride compound having an ether sulfone moiety or a method of condensing a dicarboxylic acid compound or a diacyl chloride compound with a diamine compound having an ether sulfone moiety is known.
Basically, preparation of a poly(ethersulfonamide) resin by condensation polymerization follows a process of preparing polyamide. Since the ether sulfone moiety is included in the diamine, dicarboxylic acid or diacyl chloride functional group, control of copolymerization ratio is impossible and the polymer length is limited by the diamine, dicarboxylic acid or diacyl chloride compound used as monomer.
As a method of copolymerizing the poly(ethersulfonimide or ethersulfonamide) resin allowing control of the composition of the ether sulfone moiety and the imide or amide moiety as desired and control of the polymer length through control of the amount of each component, ring-opening polymerization using cyclic oligomers as precursor may be considered. Ring-opening polymerization of polyester, polyetherketone and polyamide resins, wherein the polymerization occurs as cyclic oligomers are ring-opened in the presence of a catalyst, has been disclosed. However, copolymerization of a cyclic imide or amide with a cyclic ether sulfone has not been reported yet. Also, a method of easily controlling the copolymerization ratio by controlling the amount of the two components when preparing a copolymer of imide or amide and ether sulfone is not known yet.